Rooms that are not rectangles

Most seating tools model a room as rows times seats per row. That is a spreadsheet, not a room. A stalls curves outwards so the back rows are longer. A gangway splits row F into 1–8 and 9–16. A pillar removes D7. Numbering does not always start at 1. Force those into a rectangle and you either sell seats that do not exist or hide seats that do, and both are found out on the night.

Shape the room, row by row

Each row carries its own seat count, its own first number, the seats that are missing, where the gangways fall, and an indent for a staggered or curved rake. Rows reorder by dragging, and by arrow buttons as well — dragging is not available to everyone, and a builder only operable with a mouse is a builder some people cannot use.

Said plainly: it is a row editor with a live preview, not a canvas where you drag individual seats around a floor plan. The preview is drawn by the same code the buyer’s map and the server’s allocator use, so what you see is what will be sold rather than a second drawing that drifts from the first.

A plain rectangle stays a plain rectangle. Most rooms are one and nobody should have to draw it — shaping is something you reach for when the room needs it.

Row I, and why it is usually missing

Read aloud at a door and printed on a ticket, I and O become 1 and 0 often enough that the industry stopped using them. The builder proposes skipping both and writes the names down explicitly, so an organiser who wants row I keeps it. Sections built before this existed keep their original letters exactly — a label that silently shifts turns a sold seat into a free one on the map and an unknown seat at the door.

Best available, which mostly means together

Four people who booked together and were given four excellent seats in four different rows have been given the wrong answer. So sitting a party together outranks everything: then the centre of the row, then the front, then a penalty for stranding a single seat beside the block — the lone seat between two parties is the one that never sells, and a box office filling a house by hand knows to avoid making one.

A gangway breaks adjacency. Seats either side of a walkway are not seats together, whatever their numbers say, and a group told otherwise has been misled by software rather than by a person. When no single stretch is long enough the party is split into the fewest blocks possible and told so on screen; when there are simply not enough seats, that is a different answer and is not dressed up as a split.

Accessible seats are never handed out automatically

Wheelchair spaces and companion seats are held back and booked with the organiser directly — precisely so somebody asks about the need rather than guessing it. Best-available will not allocate one by accident, and neither will a buyer typing the seat number by hand.

Moving after the sale

A seat change is a transaction that claims the destination the same way checkout does, so two people moving into one seat at the same moment resolve to exactly one winner. Moves stay within the ticket type that was paid for: going from a £20 seat to a £200 one is an upgrade, and an upgrade is a payment, not a seat change.

Colour is never the only signal

Sections carry a name next to their colour swatch. Roughly one in twelve men has some form of colour vision deficiency, and a map encoding price tiers in red and green alone is unreadable to them — on the page where they are choosing how much to spend.